Concentrating High Purity CO₂ from Syngas after Oxy-fuel Combustion by Pressure Swing Adsorption Process

This research experimentally studied the concentration of high purity CO₂ from syngas after oxy-fuel combustion by pressure swing adsorption (PSA) process, so that the purified CO₂ can be captured and utilized/stored to reduce greenhouse gas emission. First, UOP 13X was used as adsorbent in this study due to its high adsorption amount and the selectivity of CO₂ to N₂ usually increasing with temperature. Then breakthrough curves and desorption curves were discussed by changing the feed flow rate and feed composition and were verified with a simulation program. Finally, carbon dioxide was purified by a single-bed four-step pressure swing adsorption process. The feed gas of PSA process was 95% CO₂ / 5% N₂, simulating syngas after oxy-fuel combustion. Variables such as vacuum pressure, adsorption time, cocurrent depressurization time and countercurrent depressurization time were discussed to find their effects on CO₂ recovery and purity in order to study the optimal operating conditions for obtaining high purity CO₂.